1/*
2 * Copyright 2019-2022 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2019, Oracle and/or its affiliates.  All rights reserved.
4 *
5 * Licensed under the Apache License 2.0 (the "License").  You may not use
6 * this file except in compliance with the License.  You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
9 */
10
11#include "e_os.h"
12#include <openssl/core_names.h>
13#include <openssl/core_dispatch.h>
14#include <openssl/err.h>
15#include <openssl/evp.h>
16#include <openssl/params.h>
17#include <openssl/proverr.h>
18#include "internal/packet.h"
19#include "internal/der.h"
20#include "prov/provider_ctx.h"
21#include "prov/providercommon.h"
22#include "prov/implementations.h"
23#include "prov/provider_util.h"
24#include "prov/der_wrap.h"
25
26#define X942KDF_MAX_INLEN (1 << 30)
27
28static OSSL_FUNC_kdf_newctx_fn x942kdf_new;
29static OSSL_FUNC_kdf_freectx_fn x942kdf_free;
30static OSSL_FUNC_kdf_reset_fn x942kdf_reset;
31static OSSL_FUNC_kdf_derive_fn x942kdf_derive;
32static OSSL_FUNC_kdf_settable_ctx_params_fn x942kdf_settable_ctx_params;
33static OSSL_FUNC_kdf_set_ctx_params_fn x942kdf_set_ctx_params;
34static OSSL_FUNC_kdf_gettable_ctx_params_fn x942kdf_gettable_ctx_params;
35static OSSL_FUNC_kdf_get_ctx_params_fn x942kdf_get_ctx_params;
36
37typedef struct {
38    void *provctx;
39    PROV_DIGEST digest;
40    unsigned char *secret;
41    size_t secret_len;
42    unsigned char *acvpinfo;
43    size_t acvpinfo_len;
44    unsigned char *partyuinfo, *partyvinfo, *supp_pubinfo, *supp_privinfo;
45    size_t partyuinfo_len, partyvinfo_len, supp_pubinfo_len, supp_privinfo_len;
46    size_t dkm_len;
47    const unsigned char *cek_oid;
48    size_t cek_oid_len;
49    int use_keybits;
50} KDF_X942;
51
52/*
53 * A table of allowed wrapping algorithms, oids and the associated output
54 * lengths.
55 * NOTE: RC2wrap and camellia128_wrap have been removed as there are no
56 * corresponding ciphers for these operations.
57 */
58static const struct {
59    const char *name;
60    const unsigned char *oid;
61    size_t oid_len;
62    size_t keklen; /* size in bytes */
63} kek_algs[] = {
64    { "AES-128-WRAP", ossl_der_oid_id_aes128_wrap, DER_OID_SZ_id_aes128_wrap,
65      16 },
66    { "AES-192-WRAP", ossl_der_oid_id_aes192_wrap, DER_OID_SZ_id_aes192_wrap,
67      24 },
68    { "AES-256-WRAP", ossl_der_oid_id_aes256_wrap, DER_OID_SZ_id_aes256_wrap,
69      32 },
70#ifndef FIPS_MODULE
71    { "DES3-WRAP", ossl_der_oid_id_alg_CMS3DESwrap,
72      DER_OID_SZ_id_alg_CMS3DESwrap, 24 },
73#endif
74};
75
76static int find_alg_id(OSSL_LIB_CTX *libctx, const char *algname,
77                       const char *propq, size_t *id)
78{
79    int ret = 1;
80    size_t i;
81    EVP_CIPHER *cipher;
82
83    cipher = EVP_CIPHER_fetch(libctx, algname, propq);
84    if (cipher != NULL) {
85        for (i = 0; i < OSSL_NELEM(kek_algs); i++) {
86            if (EVP_CIPHER_is_a(cipher, kek_algs[i].name)) {
87                *id = i;
88                goto end;
89            }
90        }
91    }
92    ret = 0;
93    ERR_raise(ERR_LIB_PROV, PROV_R_UNSUPPORTED_CEK_ALG);
94end:
95    EVP_CIPHER_free(cipher);
96    return ret;
97}
98
99static int DER_w_keyinfo(WPACKET *pkt,
100                         const unsigned char *der_oid, size_t der_oidlen,
101                         unsigned char **pcounter)
102{
103    return ossl_DER_w_begin_sequence(pkt, -1)
104           /* Store the initial value of 1 into the counter */
105           && ossl_DER_w_octet_string_uint32(pkt, -1, 1)
106           /* Remember where we stored the counter in the buffer */
107           && (pcounter == NULL
108               || (*pcounter = WPACKET_get_curr(pkt)) != NULL)
109           && ossl_DER_w_precompiled(pkt, -1, der_oid, der_oidlen)
110           && ossl_DER_w_end_sequence(pkt, -1);
111}
112
113static int der_encode_sharedinfo(WPACKET *pkt, unsigned char *buf, size_t buflen,
114                                 const unsigned char *der_oid, size_t der_oidlen,
115                                 const unsigned char *acvp, size_t acvplen,
116                                 const unsigned char *partyu, size_t partyulen,
117                                 const unsigned char *partyv, size_t partyvlen,
118                                 const unsigned char *supp_pub, size_t supp_publen,
119                                 const unsigned char *supp_priv, size_t supp_privlen,
120                                 uint32_t keylen_bits, unsigned char **pcounter)
121{
122    return (buf != NULL ? WPACKET_init_der(pkt, buf, buflen) :
123                          WPACKET_init_null_der(pkt))
124           && ossl_DER_w_begin_sequence(pkt, -1)
125           && (supp_priv == NULL
126               || ossl_DER_w_octet_string(pkt, 3, supp_priv, supp_privlen))
127           && (supp_pub == NULL
128               || ossl_DER_w_octet_string(pkt, 2, supp_pub, supp_publen))
129           && (keylen_bits == 0
130               || ossl_DER_w_octet_string_uint32(pkt, 2, keylen_bits))
131           && (partyv == NULL || ossl_DER_w_octet_string(pkt, 1, partyv, partyvlen))
132           && (partyu == NULL || ossl_DER_w_octet_string(pkt, 0, partyu, partyulen))
133           && (acvp == NULL || ossl_DER_w_precompiled(pkt, -1, acvp, acvplen))
134           && DER_w_keyinfo(pkt, der_oid, der_oidlen, pcounter)
135           && ossl_DER_w_end_sequence(pkt, -1)
136           && WPACKET_finish(pkt);
137}
138
139/*
140 * Encode the other info structure.
141 *
142 * The ANS X9.42-2003 standard uses OtherInfo:
143 *
144 *  OtherInfo ::= SEQUENCE {
145 *      keyInfo KeySpecificInfo,
146 *      partyUInfo [0] OCTET STRING OPTIONAL,
147 *      partyVInfo [1] OCTET STRING OPTIONAL,
148 *      suppPubInfo [2] OCTET STRING OPTIONAL,
149 *      suppPrivInfo [3] OCTET STRING OPTIONAL
150 *  }
151 *
152 *  KeySpecificInfo ::= SEQUENCE {
153 *      algorithm OBJECT IDENTIFIER,
154 *      counter OCTET STRING SIZE (4..4)
155 *  }
156 *
157 *  RFC2631 Section 2.1.2 Contains the following definition for OtherInfo
158 *
159 *  OtherInfo ::= SEQUENCE {
160 *      keyInfo KeySpecificInfo,
161 *      partyAInfo [0] OCTET STRING OPTIONAL,
162 *      suppPubInfo [2] OCTET STRING
163 *  }
164 *  Where suppPubInfo is the key length (in bits) (stored into 4 bytes)
165 *
166 * |keylen| is the length (in bytes) of the generated KEK. It is stored into
167 *   suppPubInfo (in bits). It is ignored if the value is 0.
168 * |cek_oid| The oid of the key wrapping algorithm.
169 * |cek_oidlen| The length (in bytes) of the key wrapping algorithm oid,
170 * |acvp| is the optional blob of DER data representing one or more of the
171 *   OtherInfo fields related to |partyu|, |partyv|, |supp_pub| and |supp_priv|.
172 *   This field should noramlly be NULL. If |acvp| is non NULL then |partyu|,
173 *   |partyv|, |supp_pub| and |supp_priv| should all be NULL.
174 * |acvp_len| is the |acvp| length (in bytes).
175 * |partyu| is the optional public info contributed by the initiator.
176 *   It can be NULL. (It is also used as the ukm by CMS).
177 * |partyu_len| is the |partyu| length (in bytes).
178 * |partyv| is the optional public info contributed by the responder.
179 *   It can be NULL.
180 * |partyv_len| is the |partyv| length (in bytes).
181 * |supp_pub| is the optional additional, mutually-known public information.
182 *   It can be NULL. |keylen| should be 0 if this is not NULL.
183 * |supp_pub_len| is the |supp_pub| length (in bytes).
184 * |supp_priv| is the optional additional, mutually-known private information.
185 *   It can be NULL.
186 * |supp_priv_len| is the |supp_priv| length (in bytes).
187 * |der| is the returned encoded data. It must be freed by the caller.
188 * |der_len| is the returned size of the encoded data.
189 * |out_ctr| returns a pointer to the counter data which is embedded inside the
190 *   encoded data. This allows the counter bytes to be updated without
191 *   re-encoding.
192 *
193 * Returns: 1 if successfully encoded, or 0 otherwise.
194 * Assumptions: |der|, |der_len| & |out_ctr| are not NULL.
195 */
196static int
197x942_encode_otherinfo(size_t keylen,
198                      const unsigned char *cek_oid, size_t cek_oid_len,
199                      const unsigned char *acvp, size_t acvp_len,
200                      const unsigned char *partyu, size_t partyu_len,
201                      const unsigned char *partyv, size_t partyv_len,
202                      const unsigned char *supp_pub, size_t supp_pub_len,
203                      const unsigned char *supp_priv, size_t supp_priv_len,
204                      unsigned char **der, size_t *der_len,
205                      unsigned char **out_ctr)
206{
207    int ret = 0;
208    unsigned char *pcounter = NULL, *der_buf = NULL;
209    size_t der_buflen = 0;
210    WPACKET pkt;
211    uint32_t keylen_bits;
212
213    /* keylenbits must fit into 4 bytes */
214    if (keylen > 0xFFFFFF)
215        return 0;
216    keylen_bits = 8 * keylen;
217
218    /* Calculate the size of the buffer */
219    if (!der_encode_sharedinfo(&pkt, NULL, 0, cek_oid, cek_oid_len,
220                               acvp, acvp_len,
221                               partyu, partyu_len, partyv, partyv_len,
222                               supp_pub, supp_pub_len, supp_priv, supp_priv_len,
223                               keylen_bits, NULL)
224        || !WPACKET_get_total_written(&pkt, &der_buflen))
225        goto err;
226    WPACKET_cleanup(&pkt);
227    /* Alloc the buffer */
228    der_buf = OPENSSL_zalloc(der_buflen);
229    if (der_buf == NULL)
230        goto err;
231    /* Encode into the buffer */
232    if (!der_encode_sharedinfo(&pkt, der_buf, der_buflen, cek_oid, cek_oid_len,
233                               acvp, acvp_len,
234                               partyu, partyu_len, partyv, partyv_len,
235                               supp_pub, supp_pub_len, supp_priv, supp_priv_len,
236                               keylen_bits, &pcounter))
237        goto err;
238    /*
239     * Since we allocated the exact size required, the buffer should point to the
240     * start of the alllocated buffer at this point.
241     */
242    if (WPACKET_get_curr(&pkt) != der_buf)
243        goto err;
244
245    /*
246     * The data for the DER encoded octet string of a 32 bit counter = 1
247     * should be 04 04 00 00 00 01
248     * So just check the header is correct and skip over it.
249     * This counter will be incremented in the kdf update loop.
250     */
251    if (pcounter == NULL
252        || pcounter[0] != 0x04
253        || pcounter[1] != 0x04)
254        goto err;
255    *out_ctr = (pcounter + 2);
256    *der = der_buf;
257    *der_len = der_buflen;
258    ret = 1;
259err:
260    WPACKET_cleanup(&pkt);
261    return ret;
262}
263
264static int x942kdf_hash_kdm(const EVP_MD *kdf_md,
265                            const unsigned char *z, size_t z_len,
266                            const unsigned char *other, size_t other_len,
267                            unsigned char *ctr,
268                            unsigned char *derived_key, size_t derived_key_len)
269{
270    int ret = 0, hlen;
271    size_t counter, out_len, len = derived_key_len;
272    unsigned char mac[EVP_MAX_MD_SIZE];
273    unsigned char *out = derived_key;
274    EVP_MD_CTX *ctx = NULL, *ctx_init = NULL;
275
276    if (z_len > X942KDF_MAX_INLEN
277        || other_len > X942KDF_MAX_INLEN
278        || derived_key_len > X942KDF_MAX_INLEN
279        || derived_key_len == 0) {
280        ERR_raise(ERR_LIB_PROV, PROV_R_BAD_LENGTH);
281        return 0;
282    }
283
284    hlen = EVP_MD_get_size(kdf_md);
285    if (hlen <= 0)
286        return 0;
287    out_len = (size_t)hlen;
288
289    ctx = EVP_MD_CTX_create();
290    ctx_init = EVP_MD_CTX_create();
291    if (ctx == NULL || ctx_init == NULL)
292        goto end;
293
294    if (!EVP_DigestInit(ctx_init, kdf_md))
295        goto end;
296
297    for (counter = 1;; counter++) {
298        /* updating the ctr modifies 4 bytes in the 'other' buffer */
299        ctr[0] = (unsigned char)((counter >> 24) & 0xff);
300        ctr[1] = (unsigned char)((counter >> 16) & 0xff);
301        ctr[2] = (unsigned char)((counter >> 8) & 0xff);
302        ctr[3] = (unsigned char)(counter & 0xff);
303
304        if (!EVP_MD_CTX_copy_ex(ctx, ctx_init)
305            || !EVP_DigestUpdate(ctx, z, z_len)
306            || !EVP_DigestUpdate(ctx, other, other_len))
307            goto end;
308        if (len >= out_len) {
309            if (!EVP_DigestFinal_ex(ctx, out, NULL))
310                goto end;
311            out += out_len;
312            len -= out_len;
313            if (len == 0)
314                break;
315        } else {
316            if (!EVP_DigestFinal_ex(ctx, mac, NULL))
317                goto end;
318            memcpy(out, mac, len);
319            break;
320        }
321    }
322    ret = 1;
323end:
324    EVP_MD_CTX_free(ctx);
325    EVP_MD_CTX_free(ctx_init);
326    OPENSSL_cleanse(mac, sizeof(mac));
327    return ret;
328}
329
330static void *x942kdf_new(void *provctx)
331{
332    KDF_X942 *ctx;
333
334    if (!ossl_prov_is_running())
335        return NULL;
336
337    if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL) {
338        ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
339        return NULL;
340    }
341    ctx->provctx = provctx;
342    ctx->use_keybits = 1;
343    return ctx;
344}
345
346static void x942kdf_reset(void *vctx)
347{
348    KDF_X942 *ctx = (KDF_X942 *)vctx;
349    void *provctx = ctx->provctx;
350
351    ossl_prov_digest_reset(&ctx->digest);
352    OPENSSL_clear_free(ctx->secret, ctx->secret_len);
353    OPENSSL_clear_free(ctx->acvpinfo, ctx->acvpinfo_len);
354    OPENSSL_clear_free(ctx->partyuinfo, ctx->partyuinfo_len);
355    OPENSSL_clear_free(ctx->partyvinfo, ctx->partyvinfo_len);
356    OPENSSL_clear_free(ctx->supp_pubinfo, ctx->supp_pubinfo_len);
357    OPENSSL_clear_free(ctx->supp_privinfo, ctx->supp_privinfo_len);
358    memset(ctx, 0, sizeof(*ctx));
359    ctx->provctx = provctx;
360    ctx->use_keybits = 1;
361}
362
363static void x942kdf_free(void *vctx)
364{
365    KDF_X942 *ctx = (KDF_X942 *)vctx;
366
367    if (ctx != NULL) {
368        x942kdf_reset(ctx);
369        OPENSSL_free(ctx);
370    }
371}
372
373static int x942kdf_set_buffer(unsigned char **out, size_t *out_len,
374                              const OSSL_PARAM *p)
375{
376    if (p->data_size == 0 || p->data == NULL)
377        return 1;
378
379    OPENSSL_free(*out);
380    *out = NULL;
381    return OSSL_PARAM_get_octet_string(p, (void **)out, 0, out_len);
382}
383
384static size_t x942kdf_size(KDF_X942 *ctx)
385{
386    int len;
387    const EVP_MD *md = ossl_prov_digest_md(&ctx->digest);
388
389    if (md == NULL) {
390        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
391        return 0;
392    }
393    len = EVP_MD_get_size(md);
394    return (len <= 0) ? 0 : (size_t)len;
395}
396
397static int x942kdf_derive(void *vctx, unsigned char *key, size_t keylen,
398                          const OSSL_PARAM params[])
399{
400    KDF_X942 *ctx = (KDF_X942 *)vctx;
401    const EVP_MD *md;
402    int ret = 0;
403    unsigned char *ctr;
404    unsigned char *der = NULL;
405    size_t der_len = 0;
406
407    if (!ossl_prov_is_running() || !x942kdf_set_ctx_params(ctx, params))
408        return 0;
409
410    /*
411     * These 2 options encode to the same field so only one of them should be
412     * active at once.
413     */
414    if (ctx->use_keybits && ctx->supp_pubinfo != NULL) {
415        ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_PUBINFO);
416        return 0;
417    }
418    /*
419     * If the blob of acvp data is used then the individual info fields that it
420     * replaces should not also be defined.
421     */
422    if (ctx->acvpinfo != NULL
423        && (ctx->partyuinfo != NULL
424            || ctx->partyvinfo != NULL
425            || ctx->supp_pubinfo != NULL
426            || ctx->supp_privinfo != NULL)) {
427        ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_DATA);
428        return 0;
429    }
430    if (ctx->secret == NULL) {
431        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SECRET);
432        return 0;
433    }
434    md = ossl_prov_digest_md(&ctx->digest);
435    if (md == NULL) {
436        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
437        return 0;
438    }
439    if (ctx->cek_oid == NULL || ctx->cek_oid_len == 0) {
440        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_CEK_ALG);
441        return 0;
442    }
443    if (ctx->partyuinfo != NULL && ctx->partyuinfo_len >= X942KDF_MAX_INLEN) {
444        /*
445         * Note the ukm length MUST be 512 bits if it is used.
446         * For backwards compatibility the old check is being done.
447         */
448        ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_UKM_LENGTH);
449        return 0;
450    }
451    /* generate the otherinfo der */
452    if (!x942_encode_otherinfo(ctx->use_keybits ? ctx->dkm_len : 0,
453                               ctx->cek_oid, ctx->cek_oid_len,
454                               ctx->acvpinfo, ctx->acvpinfo_len,
455                               ctx->partyuinfo, ctx->partyuinfo_len,
456                               ctx->partyvinfo, ctx->partyvinfo_len,
457                               ctx->supp_pubinfo, ctx->supp_pubinfo_len,
458                               ctx->supp_privinfo, ctx->supp_privinfo_len,
459                               &der, &der_len, &ctr)) {
460        ERR_raise(ERR_LIB_PROV, PROV_R_BAD_ENCODING);
461        return 0;
462    }
463    ret = x942kdf_hash_kdm(md, ctx->secret, ctx->secret_len,
464                           der, der_len, ctr, key, keylen);
465    OPENSSL_free(der);
466    return ret;
467}
468
469static int x942kdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
470{
471    const OSSL_PARAM *p, *pq;
472    KDF_X942 *ctx = vctx;
473    OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx);
474    const char *propq = NULL;
475    size_t id;
476
477    if (params == NULL)
478        return 1;
479    if (!ossl_prov_digest_load_from_params(&ctx->digest, params, provctx))
480        return 0;
481
482    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SECRET);
483    if (p == NULL)
484        p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY);
485    if (p != NULL && !x942kdf_set_buffer(&ctx->secret, &ctx->secret_len, p))
486        return 0;
487
488    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_X942_ACVPINFO);
489    if (p != NULL
490        && !x942kdf_set_buffer(&ctx->acvpinfo, &ctx->acvpinfo_len, p))
491        return 0;
492
493    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_X942_PARTYUINFO);
494    if (p == NULL)
495        p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_UKM);
496    if (p != NULL
497        && !x942kdf_set_buffer(&ctx->partyuinfo, &ctx->partyuinfo_len, p))
498        return 0;
499
500    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_X942_PARTYVINFO);
501    if (p != NULL
502        && !x942kdf_set_buffer(&ctx->partyvinfo, &ctx->partyvinfo_len, p))
503        return 0;
504
505    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_X942_USE_KEYBITS);
506    if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_keybits))
507        return 0;
508
509    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_X942_SUPP_PUBINFO);
510    if (p != NULL) {
511        if (!x942kdf_set_buffer(&ctx->supp_pubinfo, &ctx->supp_pubinfo_len, p))
512            return 0;
513        ctx->use_keybits = 0;
514    }
515
516    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_X942_SUPP_PRIVINFO);
517    if (p != NULL
518        && !x942kdf_set_buffer(&ctx->supp_privinfo, &ctx->supp_privinfo_len, p))
519        return 0;
520
521    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_CEK_ALG);
522    if (p != NULL) {
523        if (p->data_type != OSSL_PARAM_UTF8_STRING)
524            return 0;
525        pq = OSSL_PARAM_locate_const(params, OSSL_ALG_PARAM_PROPERTIES);
526        /*
527         * We already grab the properties during ossl_prov_digest_load_from_params()
528         * so there is no need to check the validity again..
529         */
530        if (pq != NULL)
531            propq = p->data;
532        if (find_alg_id(provctx, p->data, propq, &id) == 0)
533            return 0;
534        ctx->cek_oid = kek_algs[id].oid;
535        ctx->cek_oid_len = kek_algs[id].oid_len;
536        ctx->dkm_len = kek_algs[id].keklen;
537    }
538    return 1;
539}
540
541static const OSSL_PARAM *x942kdf_settable_ctx_params(ossl_unused void *ctx,
542                                                     ossl_unused void *provctx)
543{
544    static const OSSL_PARAM known_settable_ctx_params[] = {
545        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
546        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
547        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SECRET, NULL, 0),
548        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
549        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_UKM, NULL, 0),
550        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_X942_ACVPINFO, NULL, 0),
551        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_X942_PARTYUINFO, NULL, 0),
552        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_X942_PARTYVINFO, NULL, 0),
553        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_X942_SUPP_PUBINFO, NULL, 0),
554        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_X942_SUPP_PRIVINFO, NULL, 0),
555        OSSL_PARAM_int(OSSL_KDF_PARAM_X942_USE_KEYBITS, NULL),
556        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CEK_ALG, NULL, 0),
557        OSSL_PARAM_END
558    };
559    return known_settable_ctx_params;
560}
561
562static int x942kdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
563{
564    KDF_X942 *ctx = (KDF_X942 *)vctx;
565    OSSL_PARAM *p;
566
567    if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
568        return OSSL_PARAM_set_size_t(p, x942kdf_size(ctx));
569    return -2;
570}
571
572static const OSSL_PARAM *x942kdf_gettable_ctx_params(ossl_unused void *ctx,
573                                                     ossl_unused void *provctx)
574{
575    static const OSSL_PARAM known_gettable_ctx_params[] = {
576        OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
577        OSSL_PARAM_END
578    };
579    return known_gettable_ctx_params;
580}
581
582const OSSL_DISPATCH ossl_kdf_x942_kdf_functions[] = {
583    { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))x942kdf_new },
584    { OSSL_FUNC_KDF_FREECTX, (void(*)(void))x942kdf_free },
585    { OSSL_FUNC_KDF_RESET, (void(*)(void))x942kdf_reset },
586    { OSSL_FUNC_KDF_DERIVE, (void(*)(void))x942kdf_derive },
587    { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
588      (void(*)(void))x942kdf_settable_ctx_params },
589    { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))x942kdf_set_ctx_params },
590    { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
591      (void(*)(void))x942kdf_gettable_ctx_params },
592    { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))x942kdf_get_ctx_params },
593    { 0, NULL }
594};
595